Travelling grate sintering apparatus and the like



July 23, 1968 w. c G. TAYLOR TRAVELLING GRATE SINTERING APPARATUS ANDTHE LIKE 2 Sheets-Sheet 1 Filed June 27, 1966 FIG].

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TRAVELLING GRATE SINTERING APPARATUS AND THE LIKE Filed June 27, 1966 2Sheets-Sheet 2 FIG.2

0pm Vl z'lfred C. 6. Taylor United States Patent ABSTRACT OF THEDISCLOSURE The invention relates to sintering apparatus of the kindhaving a gas collecting hood, drop seal arrangements being providedbetween the travelling grate of the apparatus and the hood, thedrop-bars of the drop seal arrangements being carried by protuberancesfrom the sides of i the grate and which define continuous troughs alongthe sides of the grate for carrying dust out of the hood.

The present invention relates to apparatus, such as s ntering apparatus,of the kin-d having an endless travelllng grate, for example in the formof a series of pallets, for carrying material which is treated by gasesblown through the grate from the underside thereof, as the grate travelsalong, windboxes being provided beneath the grate and a gas collectinghood in the form of a tunnel being positioned over the grate. In suchapparatus the grate is, so to speak, sealed to the windboxes to preventexcessive escape of gases to the atmosphere, the seal comprising eithera grease slide arrangement which also provides a supporting track forthe travelling grate, or, if the grate has a separate supporting railtrack engaged by rollers or the like on the grate, a drop sealarrangement. In apparatus where a grease slide arrangement is provided,the guiding of the grate over its return run is usually by rollers orthe like on the grate which engage a guide track. It will be appreciatedthat such apparatus may also be operated so that over a first sectiongas is blown upwardly from the underside of the grate and over a secondsection is drawn downwardly through the grate by using pressurewindboxes over the first section and suction windboxes over the secondsection, the sealing arrangement over said second section serving toprevent excessive air being drawn directly into the suction boxes.

Grease slide and drop seal arrangements are similar insofar as they bothcomprise surfaces associated with the windboxes, for example surfaces onthe supporting frame for the windboxes, over which slide sealing membersassociated with the travelling grate. In the grease slide arrangementgrease is pumped between the sliding surfaces and in the drop sealarrangement the sealing members associated with the grate are drop barswhich slide over wear strips and are so mounted that as the wear stripswear away, drop downwardly under their own weight to take up the wearautomatically.

When such apparatus is used to manufacture agglomerated material, forexample sintered material or hardened pellets, principally of a mineralbase, dust and particles blown off the grate can fall between the sidesof the grate and the sides of the tunnel in known apparatus and caneventually block the track path of the grate. The dust under theseconditions can eventually penetrate the axle bearing enclosure of thegrate rollers which then require continuous maintenance.

Attempts have been made on existing installations to deflect the dustback on to the grate by deflector plates extending the length of thetunnel and projecting inwardly and downwardly from the sides of thetunnel to 3,393,904 Patented July 23, 1968 a position overlying thegrate, but these are not wholly effective and any attempt to install afurther rubbing seal between these deflector plotes and the grate is notpracticable because any seal surface on the sides of the grate cannot bekept in perfect alignment because of the necessary running tolerancesbetween the grate and its tracks. An object of the present invention is.to deal with this dust problem in a more efiicaceous manner thanhitherto. According to the present invention in apparatus of the kinddescribed above, there is provided a drop seal arrangement between thetunnel and grate, the drop bars of the drop seal arrangement beingsupported by protuberances from the sides of the grate which are adaptedto collect the dust blown oft the grate and thus transport the dust outof the tunnel where it can be discharged.

Certain other advantages accrue from the present invention in that theside-walls of the tunnel can be termi nated at the level of this dropseal arrangement, so that the ends of the tunnel which are sealed off toprevent gases being blown to atmosphere or air being sucked into or outof the tunnel ends need only be profiled to allow movement through themof that part of the grate above the drop seals; thus the problem ofsealing off the ends of the tunnel arising when the rollers have to passthrough the ends of the tunnel is obviated. Further by terminating thetunnel at the level of the drop seal arrangement the lower side-walls ofthe grate and the rollers and associated tracks can be exposed toatmosphere which gives ease of access for maintenance and also prolongsthe life of the lubricating grease for the rollers because the grease isnot subject to the temperature of the hot gases blown through the grate.

In cases where it is desirable to totally enclose the grate the tunnelside-walls can be extended to do so.

With the drop seal arrangement between the tunnel and the grate, asuitable rapping device can easily be installed to ensure that the dropbars are in the down position or, alternatively an up detection devicecan give warning of faulty drop bars.

In order that the invention may be readily understood, a sinteringapparatus in accordance therewith will now be described by way ofexample with reference to the two figures of the accompanying drawing,in which:

FIGURE 1 is a section through the sintering apparatus looking towardsthe discharge end, and

FIGURE 2 is an enlarged view of that part indicated at X in FIGURE 1.

Referring now to the drawing, the sintering apparatus has a travellinggrate in the form of an endless series of pallets 1 which are supportedand guided to move continuously around a closed loop through upper andlower runs. Over their upper run the pallets I carry material 2 over aseries of windboxes 3 through which hot gases are blown as indicated bythe arrows 4 to pass through the bottoms of the pallets 1 and hencethrough the material 2 to effect sintering. At the end of the upper runthe material 2 is automatically discharged from the pallets 1 and thepallets 1 return empty over their lower run which is below the windboxes3 to the reloading position. A gas collecting hood in the form of atunnel 5 is disposed over the windboxes 3 and extending from the tunnel5 in a gas take-01f duct 6.

The apparatus is supported by a girder framework as can be clearly seenin the drawings and this carries rails 7 extending along the upper runof the pallets 1 and forming a track engaged by roller 8 on the pallets1 to support and guide the pallets 1 over their upper run and rails 9extending along the lower run of the pallets 1 and which are engaged bythe rollers 8 to support and guide the pallets 1 over their lower run.

The windboxes 3 are supported longitudinally and transversely of theapparatus by members 10 and 12 respectively of the girder framework, themembers 10 and 12 being disposed closely adjacent the underside of thepallets 1 and defining the open mouths of the windboxes 3. To preventgases being blown from the windboxes 3 directly to atmosphere, a dropseal arrangement is provided between the members 10 and the pallets 1,this drop seal arrangement comprising wear strips 13 mounted on thelongitudinal members 10 at opposite sides of pallets 1 and drop bars 14mounted on the pallets 1. As can be seen more clearly in FIGURE 2, thewear strips 13 are disposed at an angle to the horizontal. As analternative to this drop seal arrangement a grease slide arrangementcould be used, in which case the rails 7 would be omitted, the supportand guidance of the pallets 1 over their upper run being by the greaseslides which replace the wear strips 13.

Deflector plates 15 extend inwardly and downwardly from the sides of thetunnel so that some of the dust and particles blown out of the bed ofmaterial 2 is deflected back into the bed.

Referring now more particularly to FIGURE 2, the sides of the pallets 1are in upper and lower sidewall sections 16 and 17, the floor 18 of thepallets 1 extending from the junction of the upper and lower sections 16and 17. Mounted on the sides of the pallets are brackets 19 which carrythe axles of aforementioned rollers 8 and drop bars 14 of drop sealarrangement. The brackets 19 each terminate at their upper end, which isabout at the level of the floors 18 of the pallets 1, in a trough 20' tothe outer side of which is mounted a drop bar 22 of a further drop sealarrangement, the associated wear strip 23 of this drop seal arrangementbeing carried by a girder 24 supporting a sand seal 25 in which thelower edge of the sheet metal structure of tunnel 5 terminates.

In operation of the apparatus dust and particles blown between thedeflector plates 15 and the sides of the tunnel falls into the troughs20 and is thus transported out of the tunnel and discharged.

The drop seal arrangement between the tunnel 5 and the pallets 1 enablesthe tunnel to terminate as shown at the girders 24 so that the rail 7,rollers 8 and lower side- .4 wall sections 17 of the pallets 1 areexposed to the atmosphere. If it is desired to extend the tunnel sidesdownwardly this can be done by casing 26 shown in dash-dot line inFIGURE 1.

It will be appreciated that a trough corresponding to the trough 20could form an independent unit bolted to the side of the grate.

I claim:

1. Apparatus such as s-intering apparatus comprising means forming atreatment zone for material defined by a succession of windboxes and agas collecting hood in the form of a tunnel disposed over saidwindboxes, a track extending through said treatment zone above saidwindboxes, an endless travelling grate for carrying said materialthrough said treatment zone, track engaging means on said grate engagingsaid track to support and guide said grate, protuberances from the sidesof said grate defining troughs which extend continuously along saidgrate for collecting dust blown off said grate and so transport suchdust out of said tunnel, and a drop seal arrangement on each side ofsaid grate between said grate and said tunnel the drop bar of said dropseal arrangements being mounted on said protuberances at a positionlaterally of the grate on the outer side of said troughs.

2. The apparatus as claimed in claim 1, wherein the lower ends of thetunnel side-walls terminate at the level of said drop seal arrangement.

3. Apparatus as claimed in claim 2, wherein the lower ends of saidtunnel side-walls terminate in sand seals and the wear strips of saiddrop seal arrangement are mounted on the supporting structure of saidsand seals.

References Cited UNITED STATES PATENTS 2,789,809 4/1957 Grabau et a1.26621 2,825,550 3/1958 Rowen 266-21 3,059,912 10/1962 Cotton 266-213,172,936 3/1965 Koontz 26621 JOHN J. CAMBY, Acting Primary Examiner.

